<div class="face">
    <p>< img class="normalFace" src="./images/upload.jpg" οnclick="fileSelect();"></p>
    <form id="form_face" enctype="multipart/form-data" style="width:auto;">
        <input type="file" name="fileToUpload" id="fileToUpload" οnchange="fileSelected();" style="display:none;">
    </form>
</div>
<script type="text/javascript">
    function fileSelect() {
        document.getElementById("fileToUpload").click();
    }

    function fileSelected() {
        // 文件选择后触发次函数
    }
</script>